Cook sweet potatoes in large pot of boiling salted water until tender, about 15 minutes. Drain well. Transfer to large bowl and puree in mixer or processor in batches. Return to pot. Mix in butter, molasses, 2 teaspoons lemon peel and 1 1/2 teaspoons nutmeg. Season with salt and pepper. (Can be prepared 1 day ahead. Cover and refrigerate.) Stir potato mixture over medium heat to rewarm and thicken slightly.

Transfer potatoes to serving bowl. Top with parsley, lemon and nutmeg.